(a) Field of the Invention
This invention relates to solid shaped powder compositions which are formed without resort to high pressure and which can be pigmented. The compositions may be employed in cosmetic applications, such as eye shadows or rouge.
(b) State of the Art
Solid powder products, particularly powder pigments used to form rouge or eye shadows, desirably contain little or no oils or waxes since dry powdered products exhibit less creasing than oil or wax containing products. Wax and oil based products are difficult to apply evenly and with the desired precision. Further, after application, these products may smear or be transferred from one surface to another, as from the eyelid to the brow area.
Conventional solid powder products have been formed by combining low levels of oils, waxes and other binders with the powder particles and subjecting the particles to high pressures. Processing of these conventional products poses difficulties since the small amounts of binder, e.g., 5-10 weight percent oil or wax, must be deposited evenly on the powder particles to insure formation of a coherent mass. The extensive beating occurring during mixing to insure uniform deposition of the binder on the powder is detrimental to some pigments. For example, pearl pigments which are of relatively large particle size are broken down. Also, pigment shade may be altered by beating during the mixing process.
Oil or wax-free powder sticks have not proven successful since those with adequate strength exhibit poor pay-off properties during use by the consumer, i.e., pay-off requires too high an application pressure. Further, the compaction step has severely circumscribed the forms into which a solid powder product can be shaped.
In some cases, it is desirable to pigment solid powder compositions, for example, when forming eyeshadows and the like. In these cases, the pigment should be uniformly distributed throughout the powder and mottling is desirably avoided. However, pigments contain residual oils which may result in a mottled appearance.
It has now been discovered that wax and oil-free solid powder products can be formed without resorting to high pressure compaction. The products can be molded to any desired shape. Further, the products have adequate strength and good pay-off when in stick or other free standing form and can be pigmented uniformly.